Mexican side Jaguares clinched a 2-0 win away to Peruvian giants Alianza Lima to move to the verge of the Copa Libertadores group stage. Jose Guadalupe Cruz's took control of the first leg with two goals late in the first half.
Michael Pedroza put Jaguares in front in the 41st minute after finishing off a move involving Damian Manso and Jorge Rodriguez. And Rodriguez doubled the lead from the penalty spot four minutes later after Christian Ramos had handled the ball in the area.
Gremio scored two away goals but twice surrendered the lead as they drew 2-2 with Liverpool in Uruguay. Andre Lima put the visitors ahead in the sixth minute, his head from a Douglas corner hitting the bar and then goalkeeper Matias Castro before going in.
Mauren Franco equalised with a free-kick three minutes later, but Douglas restored Gremio's lead. But Liverpool equalised again in the 25th minute when Nicolas Guevara headed home a corner from Franco.
The winners of the tie will play in Group 2 alongside Colombian side Junior, Bolivian giants Oriente Petrolero and Leon de Huanuco of Peru.
Gremio coach Renato Gaucho said: "The result is the important thing tonight, no question about that. We didn't play as we can, but it is important as visitors. The team did not stop fighting for one minute. For Liverpool, it was a kind of World Cup game and for us too."
In Sao Paulo, Colombian side Tolima earned a goalless draw at Brazilian giants Corinthians. The winner of that tie will go into Group 7 alongside Brazil's Cruzeiro, Argentinian champions Estudiantes and Guarani of Paraguay.